I don't have the knowledge of the locking system enough
to track this one down, but based on the stack trace it didn't really
look like an fs-specific bug (probably in the kernel itself) -
I imagine someone will get back to you soon - I'd probably
see what is said then, rather than trying more tests..
However,
if it is that reproducable you might want to go
ahead and setup verbose booting and a kernel dump device
in case whomever might need such artifacts..
cheers
